Wtf, today i want do this, i want ai ride on medium, so i changed this value on HyperSoft,UltraSoft,SuperSoft and Soft and AI use HyperSoft... this is worked for you?
Setup the vehicle file to force the other cars to use a specific HDV and in that file you can then control the tyres they use the entire settings and so on for those cars it sounds simple to me and that HDV file also points to other files so if they have only 1 compound to use or a limited fuel tank size then you can easily control that with specific HDV files for each individual car if necessary.
Rfactor 1 or even F1Challenge are really good for this. It’s as simple as editing the tracks GDB file and creating a list of all the driver names, followed by the laps they will stop on. Shame it doesn’t seem to work for rf2.